=== modified file 'database/database.mysql'
--- database/database.mysql	
+++ database/database.mysql	
@@ -395,7 +395,7 @@ CREATE TABLE locales_source (
 
 CREATE TABLE locales_target (
   lid int(11) NOT NULL default '0',
-  translation blob NOT NULL,
+  translation blob NOT NULL default '',
   locale varchar(12) NOT NULL default '',
   plid int(11) NOT NULL default '0',
   plural int(1) NOT NULL default '0',
=== modified file 'database/updates.inc'
--- database/updates.inc	
+++ database/updates.inc	
@@ -1698,3 +1698,13 @@
   }
   return array();
 }
+
+function system_update_175() {
+  $ret = array();
+  switch ($GLOBALS['db_type']) {
+    case 'mysql':
+    case 'mysqli':
+      $ret[] = update_sql("ALTER TABLE {locales_target} ALTER COLUMN translation SET DEFAULT ''");  
+  }
+  return $ret;
+}